Biomedical materials which are particularly useful as contact lens materials fall into three general classifications; hydrogels, non-hydrophilic soft materials and rigid gas permeable materials.
The chemistries of contact lens hydrogels are almost completely described by polymer and copolymer systems comprised of either 2-hydroxyethylmethacrylate (HEMA) or N-vinyl-2-pyrrolidinone (NVP), or mixtures of HEMA and NVP. Minor components such as crosslinking agents are used in these systems to control tear strength, hydrolytic stability, modulus, etc. These hydrogel systems are generally well known and have been successful on a commercial basis, but they are not without shortcomings.
Polysiloxane based elastomers have also been known in the contact lens art for some time and have enjoyed limited commercial success. In general, the silicone chemistries involve vinyl functional end capped polysiloxane polymers.
Rigid gas permeable contact lens materials are generally copolymers formed from copolymerizing acrylic or methacryl functional monomers which contain siloxane functionalities and often also contain fluorine atoms.
The present invention provides a novel monomer chemistry to the art of biomedical device materials.